Question about group selected HDR Merge

[robertb65063360]

I'm working with stacks in Lightroom- anywhere from 3 to 7 exposures in each stack. When a single stack is slected for an HDR merge, I get a preview window with deghosting optoins. However, when I select all stacks and HDR merge as a group- I have no deghosting options. Does Lightroom use the previously selected deghosting option for all merges? If not, is there a way to tell lightroom which degree of deghosting to use before a group selection HDR merge? 

[gary_sc · Accepted solution]

As good as LR is, there's no way for LR to know "how much" deghosting to apply. In addition, all the settings are sticky. So if you do a one-off with whatever settings you want, you can then run the process to automatic with those settings. If you want custom settings for each one, than that's a one-at-a-time process.

[robertb65063360]

Ok, awsome. Thank you, Gary! I usually end up merging any exterior shots (wind and blowing trees) individually. 

[GoldingD]

Does this involve using aa plug-in?

[gary_sc]

Hi David,

Nope, not at all. 

In Lightroom or ACR, if you have raw or jpg images that have different exposures based on shutter speed (not f-stop). They should be 2 stops apart (e.g., -2. 0, +2) and select them so they are all active.

Then in Lightroom, press Control-h (that's for Mac, sorry I do not remember the PC key here) and the h key, you will get an hdr image. If you do not need to set any shadow issue (aka moving object like a dog) than you can press Shift-Control-h. In addition, if you have a whole bunch of these images, you can select them all, right click on one of the images and select Stack -> select "Auto stack based on Capture time" This will make a bunch of stacks based on how fast the shutter went before the next set of images. Then you can select all of these stacks, press Shift-Control-h and go get a cup of coffee. When you get back they will all be waiting. Hint: be sure to set the check box to stack the iamges. it will clean up the mess of images into stacks.

Let me know if this makes sense. I'm going fast here.

[GoldingD]

Depending on LrC version, you can set up the stacks, leave them stacked, the go into Photo Merge, select HDR, and merge them. It used to be merging multiple sets would bog the computer down, and at some point freeze. But that got fixed, supposedly.

Now one issue, are you going the menu route to start the merge, or a keyboard shortcut, wrong keyboard shortcut will skip the previews.

Ctrl+H

vs

Ctrl+Shift+H

[GoldingD · Accepted solution]

One reminder, the settings you see in the preview screen, deghosting, etc, carry over from previous merge, so set up one merge, modify as you feel fit, then return to merge via batch. Hopefully they are all similar enough to use the same setting.

[robertb65063360]

Ok, this is how I suspected it worked. Thank you !

[vladom54566169]

Hello.

I have question about HDR merge - What is the merge logic? I have 3 fotos  - 1, 0, + 1.  Normaly I assume, that underexposed shadows and overexposed lights(sky) not using in finall merged foto.

He should take shadows from +1  and lights(sky) from -1 - RIGHT?

But sometimes is this logic not present. Shadows takes from -1.  WHY? Have somethingt to do with this problem DEGHOST or AUTO SETTINGS?

OR CAN i manually set, which foto have I use for UNDER,/OVER exposure?

Thanks

[gary_sc]

Hi, @vladom54566169, good questions, let me see if I can help. 

First off, the spread of -1, 0, +1 is insufficient if you are using JPG images. Move to -2, 0, +2. You can use the same for raw images, but since raw image already have greater depth, you can get away with -2, +2. Using all three with raw images does not hurt, it just wastes storage space. However, even knowing this, I typically shoot all three becuase I can then look at final HDR and compare it to the "0" shot and see which I like better.

Next, select the two or three images and run the "Merge to HDR." If there is movement in the image (people, animals, wind+leaves, etc.) click on the "Low, Medium, & High" buttons and see which one successfully removes any double-image artifacts. It's best to use the lowest one which repairs the issue. Then, adjust and improve the final image as your artisitic desire moves you.

Good luck!

[vladom54566169]

Thanks for info Gary.

I am using Raw, you have right, 3 Raw is sometimes problem with space and CPU....

Ok I will change  -2 up to + 2.

Almost I am shooting static nature. Forest , where is lot of underexposure and overexposure together (tree trunks vs. sky in backround)

But still I dont know , why sometimes adobe software using underexposure in -1 (or -2 I assume). He should take shadows from +1 (or +2).

Vlado

[gary_sc]

Hi @vladom54566169, why are you thinking that Adobe is using the -1/-2 shot for the shadows? What makes you think that?

[vladom54566169]

Hi Gary, 

sorry for dealy, I was on trip.

I think that, because If you look on HDR.jpg (discussion upper  from 15.7), you can see,that shadows takes from -1. 

[gary_sc]

Hi, @vladom54566169, I'm sorry, but that is not enough information for me to find the information you refer to. If you can supply a direct link to the page and where to look, I can comment better on that issue.

Nonetheless, the whole concept of taking multiple shots is for the software to determine which regions of the image can be best served by the three shots. Thus, the +2 shot will supply the items in shadows, and the -2 shot will supply the sections in bright regions of the image. How this is done is certainly beyond my pay grade.

But I have to ask: what are you seeing that leads you to think that the shadow region is relying upon the -2 photo? Please provide a screenshot for your answer.

[vladom54566169]

Hello Gary,

I had take 2 same pictures, but there is one different - text on paper -1 have low and +1 have text hight. So 100% I can know, which one is used in merge.

I am attaching again HDR.jpg, where you can see, that shadows are taken from -1.  

It should take from + 1 -  I assume. So I dont know what is the algorithm of camara raw....